In this patent application, the term ‘wires’ is used in the sense of an elongate element or rod-shaped element.
By the term ‘weld’ is understood any operation or treatment, whether or not with the addition of welding materials or gluing materials or products and whether or not accompanied by a (local) heating of the parts to be connected, which creates a durable connection without external coupling means and with a substantially mechanical connecting function.
Fences as described in EP 2 194 216 A1 and DE 10 2010 25 513 A1 are not security fences of the type to which the present invention relates, since they cannot largely prevent penetration by persons.
The clamps from the fence from EP 2 194 216 A1 can be easily broken, the wires from the fence panels from this fence can be easily cut through, and a person can easily climb over such a fence, so that the fence which is herein described cannot reliably be used to prevent penetration by persons.
Since the fence panels from the fence as described in DE 10 2010 25 513 A1 can be easily hooked together, they can also easily be unhooked from one another again, so that it is particularly easy for persons to force their way through this fence.
Security fences having security fence panels to which the present invention relates are generally erected around buildings or areas to be protected. Thus such fences are erected, for example, around military installations, nuclear installations, airports, etc. These security fences here serve to prevent persons from being able to get through to these buildings or areas, yet ensure satisfactory visibility through these fences. With such fences, it can generally be ensured that for a certain period persons are unable to break through or climb over the fence using simple hand tools. Such a fence is also generally provided with a detection system which generates an alarm signal in the event of an attempt to break through or climb over this fence. Alternatively or additionally, security staff keep sight of the fence, whereby they can observe these attempts through the fence. The said period should then preferably tally with the period within which security staff can reach the site.
Wire panels having perpendicularly intersecting wires and an appropriate mesh size are already commonly used as security fence panels of this type and are described, for example, in GB 2 480 913 A, US 2011/0062404 A1 and ZA 2005/08877. With these, security fences are erected with the aid of posts and appropriate fastening means. In the mounted state, the wire panels generally have a smaller spacing between substantially horizontally arranged wires than between substantially vertically arranged wires.
In ZA 2006/09593, a variant of such fence panels is described, wherein the first set and the second set of wires intersect at a non-perpendicular angle.
In addition, the Applicant of the present patent application has a stronger variant of such security fence panels on the market under the name “Securifor 3D”. Extra strength is here obtained by providing the security fence panels locally with a three-dimensional bend. The wires of one set are provided locally with a bend at a same place. At the level of this bend, the wires of the other set do not extend in the same plane as the wires which are arranged next to this bend.